I have never used the IV guy in Platinum. I have used the IV guy in Emerald, but do not know if they are different. I did some looking but could not find any information on the Platinum IV guys sayings, but here are Emeralds in case they overlap.

Quote:

In Emerald, you can check your IVs by speaking to a man who lives in a house just above the Pokémon Center of the Battle Frontier. He will give you an overall judgment of all the IVs and the best IV of one of your Pokémon.

You then choose the Pokémon that you need its IVs checked. He will then say:

"...Hmm...This one, overall, ..."

and then one of the following four:

If the man says Total of the six IVs is
"I would describe as being of average ability." Between 0 and 90
"I would describe as having better-than-average ability." Between 91 and 120
"I would say is quite impressive in ability!" Between 121 and 150
"I would say is wonderfully outstanding in ability!" Between 151 and 186
Then the man will proceed to mention the best IV that Pokémon possesses. If it has more than one best IV, this will be random. Talking to the man repeatedly will make him speak about the other equally best stats.

"Incidentally, the best aspect of it, I would say, is its (HP / ATTACK / DEFENSE / SPECIAL ATTACK / SPECIAL DEFENSE / SPEED) ..."

He then gives a judgment about that IV alone:

If the man says The best IV is
"That stat is relatively good." Between 0 and 15
"That stat is quite impressive." Between 16 and 25
"That stat is outstanding!" Between 26 and 30
"It's flawless! A thing of perfection!" 31
The man will then finish up his monologue with the words: "...Hm... That's how I call it."

This Emerald feature is very handy to check if your Pokémon has a perfect IV.

I have never used the IV guy in Platinum. I have used the IV guy in Emerald, but do not know if they are different. I did some looking but could not find any information on the Platinum IV guys sayings, but here are Emeralds in case they overlap.

I got that from smogon's breeding guide.

Hmm. I think that one can be adpated to the what the guy in Platinum says. i'll have to figure out how